The Cheyenne River Sioux Tribe (CRST) has endured greater than a century's worth of environmental injustices, from the effects of nearby heap-leach gold mining, to use of a portion of the reservation for an aerial gunnery range, to the purposeful flooding of over 100,000 acres of prime reservation land, including over 80,000 acres of productive river bottom lands. The primary goal of this proposal is to foster among tribal members awareness and appreciation of prominent environmental health issues sufficient to drive an organized agenda of environmental health activities, planning, and policy, for the betterment of tribal members' health and the ecology of the reservation. This goal will be accomplished through the performance of several tightly linked Specific Aims: 1) to develop, using a social network-based lay health advisor model, a cadre of tribal members that will be able to educate and train others about prominent environmental health issues; 2) to conduct, utilizing these environmental health-trained tribal members, a broad survey of tribal members' knowledge, attitudes, and behaviors relating to a range of environmental health issues; 3) to implement an organized multi-media campaign intended to outreach to tribal members and broadcast environmental health information, keying particularly on findings from the survey; and 4) to promote, using participatory action research methods, the development of a tribal environmental health advisory board that will act in a liaison role with tribal government. Underlying these aims are explicit plans to leave in place a set of enhanced skills and understanding, a program of environmental health-related activities, and momentum toward an actively managed tribal environmental health policy agenda, which together will have a high likelihood of being sustained beyond the period of this grant support.